Magnetization filters: applications to NMR imaging of elastomers

The general Fourier scheme for parameter selective imaging is subdivided into three periods: A preparation period for application of magnetization filters, an evolution period for space encoding, and a detection period for acquisition of the spectroscopic dimension. Depending on sample requirements and available time, the first and the last period can be omitted. Preparation of the initial magnetization for space encoding by appropriate filters is a powerful and time-saving way to introduce parameter-selective image contrast. This is illustrated by filters of molecular dynamics, which are sensitive to segmental motion in different time windows for contrast enhancement in composite and aged elastomers. Further contrast amplification is achieved by computing the difference of images acquired with different filter settings.